Finishing wheel and packs therefor

ABSTRACT

The rotary flap wheel has a plurality of radially extending finishing units mounted in a circumferential series on a rotary hub structure. The finishing units on the hub structure may be all abrasive type finishing packs or abrasive finishing packs used in combination with finishing units or packs of other materials as an example, sisal or cotton. Each finishing pack provided with abrasive working surfaces includes a stack of abrasive sheets clamped at their inner radial ends between the arms of a clamping element or clip, which is mounted on the hub structure by an elongated pin located adjacent the outer periphery of the hub structure. Each abrasive finishing pack has a leading sheet, a trailing sheet, and a plurality of intermediate sheets between the leading and trailing sheets, with the sheets having a relatively abrasive surface on one circumferential side thereof and a relatively non-abrasive or smooth-faced surface on the opposite side thereof. The leading sheet of each abrasive finishing pack has the abrasive surface thereon disposed to face opposite to the direction of rotation of the hub structure, with the intermediate and trailing sheets of each abrasive finishing pack having the abrasive surfaces thereon facing uniformly in the direction of rotation of the hub structure. Thus, the non-abrasive or smooth-faced external surface of the leading sheet of each abrasive finishing pack engages a non-abrasive or smooth-faced surface on the trailing side of the finishing unit located forwardly thereof in the direction of rotation of the hub structure.

United States Patent [1 1 Belanger 1 Get. 30, 1973 1 1 FINISHING WHEEL AND PACKS THEREFOR 75] Inventor: James A. Belanger, Livonia, Mich. [73] Assignee: Belanger, Inc., Northville, Mich.

[221 Filed: May 15, 1972 211 Appl. No.: 253,236

Related U.S. Application Data [63] Continuation-impart of Ser. No. 155,733, June 23, 1971, and a continuation-in-part of Ser. No. 885,734, Dec. 17, 1969, Pat. No. 3,685,217.

[52] U.S. Cl. 51/332, 51/394 Primary ExaminerOthell M. Simpson Attorney-Charles P. Rutherford et a1.

[57] ABSTRACT The rotary flap wheel has a plurality of radially extending finishing units mounted in a circumferential series on a rotary hub structure. The finishing units on the hub structure may be all abrasive type finishing packs or abrasive finishing packs used in combination with finishing units or packs of other materials as an example, sisal or cotton. Each finishing pack provided with abrasive working surfaces includes a stack of abrasive sheets clamped at their inner radial ends between the arms of a clamping element or clip, which is mounted on the hub structure by an elongated pin located adjacent the outer periphery of the hub structure. Each abrasive finishing pack has a leading sheet, a trailing sheet, and a plurality of intermediate sheets between the leading and trailing sheets, with the sheets having a relatively abrasive surface on one circumferential side thereof and a relatively non-abrasive or smooth-faced surface on the opposite side thereof. The leading sheet of each abrasive finishing pack has the abrasive surface thereon disposed to face opposite to the direction of rotation of the hub structure, with the intermediate and trailing sheets of each abrasive finishing pack having the abrasive surfaces thereon facing uniformly in the direction of rotation of the hub structure. Thus, the non-abrasive or smooth-faced external surface of the leading sheet of each abrasive fin- 8 Claims, 3 Drawing Figures FINISHING WHEEL AND PACKS THEREFOR CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation-in-part of each of my co-pending applications, Ser. No. 155,733, filed June 23, 1971 and Ser. No. 885,734 filed Dec. 17, 1969 now US. Pat. No. 3,685,217.

My co-pending application. Ser. No. 155,733 discloses the type of forked-section, clip-like pack clamping member which pivots or mounts each pack on the BACKGROUND OF THE INVENTION 1. Field of the Invention The improved abrasive packs of the invention, as mounted on a rotary hub structure, finds application in a large number of rotative material finishing operations, specifically, in the rough or finish abrasive working, brushing, buffing, burnishing or polishing of metal or non-metal parts, in which the use of a stacked pack ofabrasive sheets is indicated.

2. Description of the Prior Art The Patent to Jeske, No. 3,099,113 of July 30, 1963, is the most pertinent prior art disclosure of which I am aware in reference to the improved abrasive pack or unit of the present invention. However, this work wheel disclosure does not relate to a special orientation relative to one another of a number of identical stacked abrasive sheets in an improved pack, nor does it relate to provisions as illustrated herein for mounting such a pack in an individual freely pivoted way upon a rotary hub structure.

SUMMARY OF THE INVENTION The base concept of the invention is applicable to wheels using all abrasive finishing units or abrasive units in combination with finishing units of other materials. The concept is a very simple one, indeed, and the breaking down due to abrasive material on the leading sheet whipping or snapping into the trailing sheet on the pack in front; yet the intermediate and trailing abrasive sheets, as arranged with their own individual abrasive surfaces uniformly facing circumferentially in the direction of rotation of the wheel, have fully effective finishing action.

The invention also is an improvement in its use of sheet stack clamping and pack pivoting components of a one-piece extruded nature, per my co-pending application, Ser. No. 155,733. Such use in combined assembly with the improved stacked sheet subassembly enables a very strong clamping engagement with the radially inner extremity of the latter. This is by reason of the mutually facing abrasive inner surfaces of the circumferentially end-most sheets of the stack, which surfaces bite firmly at said radial extremity against the interposed sheets.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view of a rotary hub structure of the improved abrasive wheel, showing a portion of a full circumferential array of like abrasive packs as applied thereto and being constituted in accordance with the invention;

FIG. 2 is a fragmentary view further showing structural features of the hub and pack combination, being stack-wise in each pack, the circumferentially extending leading sheet, structurally indistinguishable, per se, from the other intermediate abrasive and trailing sheets of the pack, has a smooth or non-abrasive external surface facing circumferentially outwardly of the intermediate and trailing sheets of the pack in the direction of rotation. The abrasive surface on the intermediate and trailing sheets of each pack face in the direction of r0.

the overall life of the individual packs by minimizing wear on the sheets and preventing the sheets from partially broken away and vertically sectioned on the broken but generally radial line 22 of FIG. 1; and

FIG. 3 is a perspective view of the abrasive finishing pack.

DESCRIPTION OF A PREFERRED EMBODIMENT A typical abrasive finishing wheel according to the invention, as generally designated by the reference numer-al 10, will basically comprise a driving hub-carried mounting plate unit or structure 12, and a multiplicity of identical abrasive sheet packs or units, each generally numbered 14. The wheel 10 may consist entirely of abrasive type finishing packs 14 or any number of such packs may be used with other types of finishing units, not shown, containing other materials such as sisal, cotton, etc. The finishing units, whether consisting of abrasive or other type materials, are mounted individually to the structure 12 in equal circumferential spacing about the latter and relative to one another. The number of packs may, of course, vary, but in general and by preference the circumferential array or complement thereof is such as to afford, when flexed in rotative finishing engagement with the workpiece, a substantially continuous circumferential characteristic at the outer extremities of the-packs l4.

Each of the abrasive finishing packs 14 used in the wheel 10 comprises a combination of a sub-assembly 15 of a number of identical abrasive sheets, which are disposed in a novel stacked manner to be described, and an appropriate clip member or element 16 by which the stack sheets are clamped together and pivotally mounted to wheel hub structure 12. The sheets of sub-assembly 15 are, as an example, of plain rectangular outline and may illustratively be of an abrasive coated, emery-type cloth or fabric, or of any other structural composition, as mentioned in my co-pending applications or as used in the art, which presents one relatively non-abrasive surface and is therefore suited to my present purpose. It should be appreciated that the outer-working edges of each pack 14 may be straight as shown or contoured to fit the work. In addition the sheets of the pack 14 may be slashed to allow greater flexibility and enable the finishing of contours without pre-contouring the pack as is well known in the art.

The pivoting clamp or clip component 16 for each pack 14 is preferably a rigid section of a metallic or non-metallic extrusion such as is illustrated in FIGS. l-3 of my co-pending application, Ser. No. 155,733, and described in detail therein. Other clip embodiments of that application are also suitable; indeed, it may be found desirable to utilize other forms of sheet securing and pivoting means, as an example, as are illustrated and described in my other co-pending application, Ser. No. 885,734, referred to above or in my U.S. Pat. Nos. 3,535,833 and 3,626,646.

Member or section 16 is coextensive in axial length with the stack 15, so that these components of pack 14 are axially confined quite closely at opposite sides thereof by the two axially end-most plates 18 of the hub mounting structure 12, yet are free to pivot individually in action relative to those plates, as well as relative to an optional intermediate plate 18' of the same structure. In general conformity with what is shown and described in my application Ser. No. 885,734, said plates, as an example, are spaced axially from one another by tubular sleeves 19 encircling elongated securing pins 20, four in number (FIG. 1), which pass through aligned openings in plates 18, 18'. Opposite ends of said pins are welded at 21 to end plates 18, or may be rigidly end-restrained relative thereto, as by nut and screw means, thereby constituting the plate assembly as s rigid structure 12. However, prior to completion of this a series of assembly pack pivoting pins 22, in a number equalling the abrasive packs 14 and equally spaced circumferentially about the plates 18 in parallelism with the securing pins 20, are seated in inner recesses 23 of those plates, having been passed through openings in the intermediate plate 18, if present. The abrasive finishing pack 14 may also be used with other forms of hub structures, as an example, as shown in my co-pending application Ser. No. 885,734 and in my U.S. Pat. Nos. 3,535,833 and 3,621,622.

As best shown in FIG. 3, the clamping and pivoting clip member 16 (described in greater detail in application, Ser. No. 155,733) presents a pair of integrally connected, parallel clamping arms or furcations 24, these arms merging integrally into a more block-like radially inner body portion 25 of the member 16, at which portion said member pivotally mounts the pack unit 14 to the wheel plate assembly or hub structure 12 on an individual transverse pivot pin 22 of that assembly.

For this purpose, the body 25 of each member 16 is formed to provide a key-hole shaped opening 26 presenting reentrant projections at 27 which wrap radially outwardly around the pivoting pin 22, with pivoting clearance relative to the latter. Relatively wide mouth portions of the keyhole openings 26 adjacent the clip arms 24 are shaped to afford shoulder surfaces radially inwardly abutted by the end of the sheet stack 15, and

with the latter thus positioned between the arms 24,

wheel structure featuring an intermediate mounting plate component 18', a radially inner recess 30 is formed in member 16 to straddle such intermediate component 18', per application Ser. No. 885,734.

Pursuant to the present improvement, the stacked sheet sub-assembly 15 of abrasive pack 14 is constituted, as perhaps best illustrated in FIG. 3, of a number of like rectangular, abrasive-faced sheets, with the working edges straight, contoured or slashed, including a pair of circumferentially outer or endmost sheets, specially designated 32, forming a leading sheet and a trailing sheet, and a variable number of intermediate sheets 33 interposed therebetween, all of such sheets 32, 33 being rigidly secured in association therewith by the stapled pivoting clip member 16. All sheets feature a face covering on one surface thereof of granular emery or like abrasive material 34, as indicated by stippling in FIGS. 2 and 3.

More specifically, the stack arrangement is one in which relatively smooth and non-abrasive surfaces 35 of the two endmost leading and trailing sheets 32 face outwardly in opposite circumferential directions, their abrasive coated surfaces 34 facing toward one another and the interposed set of sheets '33. The intermediate sheets 33 and the trailing sheet 32 have their abrasive surfaces 34 facing in the same circumferential direction, namely the direction of rotation of the wheel, as indicated by an arcuate arrow in FIG. 1. Accordingly, an abrasive surface 34 of the leading sheet 32 is in contact with a similar abrasive surface 34 of the adjacent intermediate sheet 33; while the abrasive surface 34 of the trailing sheet 32 engages against the relatively smooth surface 35 of the intermediate sheet 33 next adjacent to it.

One benefit of this arrangement resides in the fact that, as strongly clamped by clip 16 adjacent a radially inner end of the stack 15, the abrasive-to-abrasive relationship of two sheets of the stack contributes a measure of additional positive interlock of the stack components against centrifugal displacement radially. However, as indicated above, the main advantage is that each and every one of the packs 14 will have a smooth and comparatively non-wearing engagement of its sheet sub-assembly 15 with like packs or packs or non-abrasive material on either circumferential side thereof as these packs run in limited sliding engagement with one another under flexure in operation, as indicated in dot-dash line in FIG. 1. The life of the finishing unit 14 is materially lengthened, without significant diminution in its effectiveness as an abradant, by reason of the orientation of sheets pursuant to the improvement. The life of the wheel 10 is also increased.

Prior to my invention I observed that abrasive flap wheels and combination abrasive and cloth wrapped sisal flap wheels do not wear out but rather the various finishing flaps or units break down. This observation applies to both straight abrasive wheels and combination wheels. The breaking or deterioration of the finishing flaps or packs occurs during the operation of the wheel. As the coated abrasive flap or pack leaves the workpiece the abrasive surface on the leading sheet whips or snaps into the backing of the trailing sheet of the pack ahead of it. This continual colliding of abrasive grains into the backing on the leading pack breaks down the finishing flaps in a relatively short period of time. With the present invention the leading sheet of each abrasive finishing pack is reversed and faces counter to the direction of rotation and thus the abrasive surface thereon is prevented from coming into contact with the exposed backing on the leading pack. Such a construction greatly improves the coated abrasives effectiveness, increases the life of the packs and the wheels, whether straight abrasive or abrasive combined with other material.

lt should be understood that the finishing packs 14 may be mounted permanently in the hub structure 12, as shown in the drawing, thus forming a throw-away type wheel; or the finishing packs 14 may be mounted in a hub structure of a reuseable or repackable type wheel which permits the packs 14 after wear to be removed from the hub structure and replaced with new finishing packs.

The term abrasive sheets as used in the claims is intended to comprehend flexible paper, cloth, fabric, or other sheet or fill material coated or otherwise provided with abrasive particles or treated to perform various work-type finishing operations on metals or other materials.

What is claimed is:

1. In a rotary finishing pack characterized by a plurality of abrasive sheets having means to secure the same together as stacked circumferentially endmost' and intermediate sheets of the pack, said endmost sheets defining the leading sheet and the trailing sheet of the pack, said sheets each having a relatively abrasive surface on one circumferential side thereof and a relatively non-abrasive surface on the opposite side thereof; the improvement according to which the leading sheet of the pack has the abrasive surface thereon disposed to face opposite to the direction of rotation of the pack and being adapted to contact the abrasive surface on the adjacent intermediate sheet, the intermediate and trailing sheets of the pack having the abrasive surfaces thereof facing uniformly in the direction of rotation of the pack.

2. The pack improvement of claim 1, in which a plurality of said packs are disposed in an array extending of the trailing sheet of the pack located forwardly thereof in the direction of rotation.

3. The pack improvement of claim 2, in which said sheet-securing means of the several packs also pivotally mounts the same on the wheel structure.

4. The pack improvement of claim 1, in which said sheet-securing means comprises a relatively rigid, axially elongated element clamping said sheets as a stack.

tation on a wheel axis, said members having circumfercircumferentially about the axis of said rotation, each entially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 2, said mounting means of the several packs engaging the respective pin elements of the wheel structure.

7. The combination as a rotary finishing wheel of at least two coaxial and axially spaced, circumferentially extending members constituting parts of said wheel structure and adapted to be drivingly connected for rotation on a wheel axis, said members having circumferentially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 3, said mounting means of the several packs pivotally engaging the respective pin elements of the wheel structure.

8. The combination as a rotary finishing wheel of at least two coaxial and axially spaced, circumferentially extending members constituting parts of said wheel structure and adapted to be drivingly connected for rotation on a wheel axis, said members having circumferentially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 5, said mounting elements of the several packs being engaged at the aperturing thereof with the respective pin elements of the wheel structure. 

1. In a rotary finishing pack characterized by a plurality of abrasive sheets having means to secure the same together as stacked circumferentially endmost and intermediate sheets of the pack, said endmost sheets defining the leading sheet and the trailing sheet of the pack, said sheets each having a relatively abrasive surface on one circumferential side thereof and a relatively non-abrasive surface on the opposite side thereof; the improvement according to which the leading sheet of the pack has the abrasive surface thereon disposed to face opposite to the direction of rotation of the pack and being adapted to contact the abrasive surface on the adjacent intermediate sheet, the intermediate and trailing sheets of the pack having the abrasive surfaces thereof facing uniformly in the direction of rotation of the pack.
 2. The pack improvement of claim 1, in which a plurality of said packs are disposed in an array extending circumferentially about the axis of said rotation, each pack having means adjacent a radially inner end thereof to mount the same on a rotary wheel structure, with the non-abrasive surface on the leading sheet of each pack adapted to contact the non-abrasive surface of the trailing sheet of the pack located forwardly thereof in the direction of rotation.
 3. The pack improvement of claim 2, in which said sheet-securing means of the several packs also pivotally mounts the same on the wheel structure.
 4. The pack improvement of claim 1, in which said sheet-securing means comprises a relatively rigid, axially elongated element clamping said sheets as a stack.
 5. The pack improvement of claim 2, in which said sheet-securing means comprises a relatively rigid, axially elongated element clamping said sheets as a stack, the elements of the several packs axially apertured to effect the mounting thereof to said wheel structure.
 6. The combination as a rotary finishing wheel of at least two coaxial and axially spaced, circumferentially extending members constituting parts of said wheel structure and adapted to be drivingly connected for rotation on a wheel axis, said members having circumferentially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 2, said mounting means of the several packs engaging the respective pin elements of the wheel structure.
 7. The combination as a rotary finishing wheel of at least two coaxial and axially spaced, circumferentially extending members constituting parts of said wheel structure and adapted to be drivingly connected for rotation on a wheel axis, said members having circumferentially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 3, said mounting means of the several packs pivotally engaging the respective pin elements of the wheel structure.
 8. The combination as a rotary finishing wheel of at least two coaxial and axially spaced, circumferentially extending members constituting parts of said wheel structure and adapted to be drivingly coNnected for rotation on a wheel axis, said members having circumferentially spaced pin elements paralleling said axis, and a plurality of abrasive packs as improved in accordance with claim 5, said mounting elements of the several packs being engaged at the aperturing thereof with the respective pin elements of the wheel structure. 